We have opted to use our UPS shipper number for shipping of orders from our own facility. It is very difficult to find the label generation workflow in Shopify documentation for this setup. All documentation seems to address using Shopify Shipping to buy labels on the Shopify accounts. Does anyone know how this workflow goes? Surely it's possible to get data for label into UPS without manually moving over (if not using ShipStation or other 3rd party solution). Please help.
If you're using UPS US you should be able to add UPS as a BYOA account (your own account number). Once that connection is setup, you'll be able to buy UPS labels from Shopify Admin but through your account. The docs are indeed lacking on this; up to Step 5 is what you would need to do for it to just "show up":